In an article entitled "The Trazor.TM.--A New Input Device" by the inventor hereof and A. J. Rider, published in "Gametronics Proceedings" Volume 1, January 1977, pages 115-120, reference was made to ways to make electronic musical instruments that would be easier to play than most musical instruments, and a musical instrument was hypothesized having a two-dimensional control surface that would generate tones whose pitch corresponded to finger position in one axis, and whose tone qualtiy, or timbre corresponded to finger position in the other axis and, further that such musical instrument could have a second such control surface used by the other hand to control loudness and vibrato.